Moving picture coding method, moving picture coding apparatus, moving picture decoding method, and moving picture decoding apparatus

ABSTRACT

The moving picture coding method for coding an input image includes: converting a value of a first parameter into a first binary signal, the first parameter identifying a type of a sample offset process to be applied to a reconstructed image corresponding to the input image; and coding at least a portion of the first binary signal through bypass arithmetic coding using a fixed probability.

FIELD

One or more exemplary embodiments disclosed herein relate to anapparatus and a method for coding or decoding a moving picture, and inparticular to arithmetic coding or arithmetic decoding on a sampleadaptive offset (SAO) parameter.

BACKGROUND

Recent years have seen the significant technical development in digitalvideo apparatuses, and increasing chances for compression-coding a video(moving picture) signal (a plurality of pictures arranged in timeseries) and recording the video signal onto recording media such as DVDsand hard disks or distributing the video signal on the Internet. TheH.264/AVC (MPEG-4 AVC) is one of the image coding standards, and theHigh Efficiency Video Coding (HEVC) standard is currently beingconsidered as a next-generation standard.

The HEVC standard described in NPL 1 proposes a sample offset processcalled SAO. The SAO process is a process for adding an offset value to asample value (pixel value) in an image (reconstructed image) decodedfrom a bitstream. Accordingly, the reconstructed image in which the SAOprocess has been performed enables faithful reproduction of an originalimage (input image) before coding and reduction in image degradation bythe coding.

CITATION LIST Non Patent Literature

[NPL 1] Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG16WP3 and ISO/IEC JTC1/SC29/WG11, 9th Meeting: Geneva, CH, 27 Apr.-7 May2012, JCTVC-I0602_CDTexts_r3.doc, BoG report on integrated text of SAOadoptions on top of JCTVC-I0030,

http://phenix.it-sudparis.eu/jct/doc_end_user/docurnents/9_Geneva/wg11/JCTVC-I0602-v4.zip

SUMMARY Technical Problem

The moving picture coding/decoding processes using the conventionalsample offset process require suppression of decrease in the codingefficiency and acceleration of processing or reduction in the processingload.

Thus, one or more exemplary embodiments disclosed provide a movingpicture coding method and a moving picture decoding method that canaccelerate processing or reduce the processing load while suppressingdecrease in the coding efficiency in the moving picture coding/decodingprocesses using the sample offset process.

Solution to Problem

The moving picture coding method according to an aspect of the presentdisclosure is a moving picture coding method for coding an input image,and includes: converting a value of a first parameter into a firstbinary signal, the first parameter identifying a type of a sample offsetprocess to be applied to a reconstructed image corresponding to theinput image; and coding at least a portion of the first binary signalthrough bypass arithmetic coding using a fixed probability.

The general or specific aspects may be implemented by a system, anapparatus, an integrated circuit, a computer program, or acomputer-readable recording medium, or by an arbitrary combination ofthe system, the apparatus, the integrated circuit, the computer program,and the recording medium.

Advantageous Effects

The moving picture coding and decoding methods according to an aspect ofthe present disclosure can accelerate processing or reduce theprocessing load while suppressing decrease in the coding efficiency, inthe moving picture coding/decoding processes using the sample offsetprocess.

BRIEF DESCRIPTION OF DRAWINGS

These and other advantages and features will become apparent from thefollowing description thereof taken in conjunction with the accompanyingDrawings, by way of non-limiting examples of embodiments disclosedherein.

FIG. 1 is a block diagram illustrating a configuration of a movingpicture coding apparatus according to Embodiment 1.

FIG. 2 is a flowchart indicating processes performed by the movingpicture coding apparatus according to Embodiment 1.

FIG. 3 is a block diagram illustrating an internal configuration of anSAO parameter variable length coding unit according to Embodiment 1.

FIG. 4 is a flowchart indicating processes performed by the SAOparameter variable length coding unit according to Embodiment 1.

FIG. 5 is a block diagram illustrating an internal configuration of ansao_type_idx coding unit according to Embodiment 1.

FIG. 6 is a flowchart indicating processes performed by the sao_type_idxcoding unit according to Embodiment 1.

FIG. 7 is a table indicating a correspondence between non-binary signalsand binary signals according to Embodiment 1.

FIG. 8 is a table indicating a correspondence between binIdxs andcontexts according to Embodiment 1 and Variations 1 and 2.

FIG. 9 is a table showing a result of experiment in which the codingefficiencies between the conventional technique and Embodiment 1 andVariations 1 and 2 are compared.

FIG. 10 is a table indicating a correspondence between non-binarysignals and binary signals according to Variation 3.

FIG. 11 is a table indicating a correspondence between binIdxs and acontext according to Variation 3.

FIG. 12 is a block diagram illustrating a configuration of a movingpicture decoding apparatus according to Embodiment 2.

FIG. 13 is a flowchart indicating processes performed by the movingpicture decoding apparatus according to Embodiment 2.

FIG. 14 is a block diagram illustrating an internal configuration of anSAO parameter variable length decoding unit according to Embodiment 2.

FIG. 15 is a flowchart indicating processes performed by the SAOparameter variable length decoding unit according to Embodiment 2.

FIG. 16 is a block diagram illustrating an internal configuration of ansao_type_idx decoding unit according to Embodiment 2.

FIG. 17 is a flowchart indicating processes performed by thesao_type_idx decoding unit according to Embodiment 2.

FIG. 18A is a block diagram illustrating a configuration of a movingpicture coding apparatus according to another Embodiment.

FIG. 18B is a flowchart indicating processes performed by the movingpicture coding apparatus according to the other Embodiment.

FIG. 19A is a block diagram illustrating a configuration of a movingpicture decoding apparatus according to the other Embodiment.

FIG. 19B is a flowchart indicating processes performed by the movingpicture decoding apparatus according to the other Embodiment.

FIG. 20 illustrates an overall configuration of a content providingsystem for implementing content distribution services.

FIG. 21 illustrates an overall configuration of a digital broadcastingsystem.

FIG. 22 illustrates a block diagram of an example of a configuration ofa television.

FIG. 23 illustrates a block diagram illustrating an example of aconfiguration of an information reproducing/recording unit that readsand writes information from or on a recording medium that is an opticaldisc.

FIG. 24 illustrates an example of a configuration of a recording mediumthat is an optical disc.

FIG. 25A illustrates an example of a cellular phone.

FIG. 25B illustrates a block diagram of an example of a configuration ofthe cellular phone.

FIG. 26 illustrates a structure of multiplexed data.

FIG. 27 schematically illustrates how each stream is multiplexed inmultiplexed data.

FIG. 28 illustrates how a video stream is stored in a stream of PESpackets in more detail.

FIG. 29 illustrates a structure of TS packets and source packets in themultiplexed data.

FIG. 30 illustrates a data structure of a PMT.

FIG. 31 illustrates an internal structure of multiplexed datainformation.

FIG. 32 illustrates an internal structure of stream attributeinformation.

FIG. 33 illustrates steps for identifying video data.

FIG. 34 illustrates a block diagram illustrating an example of aconfiguration of an integrated circuit for implementing a moving picturecoding method and a moving picture decoding method according to each ofEmbodiments.

FIG. 35 illustrates a configuration for switching between drivingfrequencies.

FIG. 36 illustrates steps for identifying video data and switchingbetween driving frequencies.

FIG. 37 illustrates an example of a look-up table in which the standardsof video data are associated with the driving frequencies.

FIG. 38A illustrates an example of a configuration for sharing a moduleof a signal processing unit.

FIG. 38B illustrates an example of a configuration for sharing a moduleof a signal processing unit.

DESCRIPTION OF EMBODIMENTS

(Knowledge on which the Present Disclosure is Based)

In the SAO process, pixels included in a reconstructed image areclassified into categories. For each of the categories, an offset valuecorresponding to the category is added to a pixel value belonging to thecategory. There are plural methods for classifying pixels. Specifically,arithmetic coding is performed on a parameter indicating aclassification method used in the actual coding (that is, parameter(sao_type_idx) for identifying a type of a sample offset process), andthe parameter is added to a bitstream.

Furthermore, in accordance with the HEVC standard, a signal to be codedis converted (binarized) from a non-binary signal to a binary signal(signal representing 0 and 1), and then the arithmetic coding isperformed on the binary signal.

The binary signal is a signal including at least one of bitsrepresenting one of two symbols (0 and 1). Each of the bits is alsoreferred to as “bin” in the Description. Here, the binary signal is alsoreferred to as “bin string”.

In accordance with the HEVC standard, two types of arithmetic coding aredefined, namely, context-adaptive arithmetic coding and bypassarithmetic coding. In the context-adaptive arithmetic coding, arithmeticcoding is performed on a binary signal using a symbol occurrenceprobability adaptively selected based on a context. Furthermore, in thebypass arithmetic coding, arithmetic coding is performed on a binarysignal using a fixed symbol occurrence probability (for example, 50%).

More specifically, in the context-adaptive arithmetic coding, a contextis selected, for example, per bin included in a binary signal to becoded. Then, probability information of the selected context is loaded,and arithmetic coding is performed on the bin using a symbol occurrenceprobability identified by the probability information. Furthermore, theprobability information (symbol occurrence probability) of the selectedcontext is updated according to a value (symbol) of the bin in which thearithmetic coding has been performed.

In contrast, in the bypass arithmetic coding, arithmetic coding isperformed on a bin by fixing the symbol occurrence probability to 50%without using any context. Thus, no probability information on thecontext is loaded or updated in the bypass arithmetic coding.

Conventionally, since it seems that each bin included in a binary signalcorresponding to sao_type_idx has a bias in the symbol occurrenceprobability, the context-adaptive arithmetic coding is performed on thebin. Thus, the processing load for loading or updating probabilityinformation on a context increases in the conventional coding ofsao_type_idx. Furthermore, when arithmetic coding is performed on twobits using the same context, the arithmetic coding on the second bitcannot be started until the context updating process on the first bit iscompleted. Thus, the arithmetic coding on sao_type_idx becomessequential, and the throughput is reduced.

The moving picture coding method according to an aspect of the presentdisclosure is a moving picture coding method for coding an input image,and includes: converting a value of a first parameter into a firstbinary signal, the first parameter identifying a type of a sample offsetprocess to be applied to a reconstructed image corresponding to theinput image; and coding at least a portion of the first binary signalthrough bypass arithmetic coding using a fixed probability.

Accordingly, the portion of the first binary signal corresponding to thevalue of the first parameter for identifying a type of the sample offsetprocess can be coded through the bypass arithmetic coding. The number ofloading and updating of probability information corresponding to acontext can be reduced more than that of coding all the binary signalsby the context-adaptive arithmetic coding. Furthermore, since the bypassarithmetic coding does not require updating the probability information,arithmetic coding can be performed, in parallel, on bits included in abinary signal.

Furthermore, since the binary signal corresponding to the value of thefirst parameter conventionally has a bias in the symbol occurrenceprobability, it seems that the coding efficiency significantly decreaseswhen the binary signal is coded through the bypass arithmetic coding.However, the present disclosure reveals that the coding efficiency doesnot significantly decrease even when at least a portion of the binarysignal corresponding to the value of the first parameter is codedthrough the bypass arithmetic coding.

In other words, by coding at least the portion of the binary signalcorresponding to the value of the first parameter for identifying a typeof the sample offset process through the bypass arithmetic coding,processing can be accelerated or the processing load can be reducedwhile decrease in the coding efficiency can be suppressed.

For example, a first portion of the first binary signal may be codedthrough context-adaptive arithmetic coding, and a second portion of thefirst binary signal may be coded through the bypass arithmetic codingwhen the first binary signal includes the second portion subsequent tothe first portion.

Accordingly, the first portion of the binary signal can be coded throughthe context-adaptive arithmetic coding, and the second portion of thebinary signal can be coded through the bypass arithmetic coding. Thus,it is possible to switch the arithmetic coding between the first portionhaving a larger bias in the symbol occurrence probability and the secondportion having a smaller bias in the symbol occurrence probability, anddecrease in the coding efficiency can be further suppressed.

For example, the sample offset process may not be applied to thereconstructed image when the value of the first parameter is equal to apredetermined value, and the first portion of the first binary signalmay indicate whether or not the value of the first parameter is equal tothe predetermined value.

Accordingly, the first portion indicating whether or not the value ofthe first parameter is equal to the predetermined value can be codedthrough the context-adaptive arithmetic coding. In other words, thefirst portion indicating whether or not the sample offset process isapplied to the reconstructed image can be coded through thecontext-adaptive arithmetic coding. Since the portion indicating whetheror not the sample offset process is applied to the reconstructed imagehas a larger bias in the symbol occurrence probability, decrease in thecoding efficiency can be further suppressed.

For example, the first portion of the first binary signal may becomposed of a first bit of the first binary signal, and the secondportion of the first binary signal may be composed of the remaining bitsof the first binary signal.

Accordingly, the first bit of the binary signal can be coded through thecontext-adaptive arithmetic coding, and the remaining bits of the binarysignal can be coded through the bypass arithmetic coding.

For example, the moving picture coding method may further include:converting at least one of a value of a second parameter and a value ofa third parameter into a second binary signal, the second parameteridentifying an intra prediction mode, the third parameter identifying acandidate to be used for inter prediction from a list of candidates eachincluding at least one motion vector; coding a first portion of thesecond binary signal through the context-adaptive arithmetic coding; andcoding a second portion of the second binary signal through the bypassarithmetic coding when the second binary signal includes the secondportion subsequent to the first portion, wherein a bit length of thefirst portion of the first binary signal may be identical to a bitlength of the first portion of the second binary signal.

Accordingly, since switching the arithmetic coding between the firstparameter for identifying a type of a sample offset process and anotherparameter (second parameter or third parameter) can be standardized, theconfiguration of the coding apparatus can be simplified.

For example, the first binary signal may include one or more first bitshaving a first symbol when the value of the first parameter is largerthan 0, the number of the first bits being equal to the value of thefirst parameter, and the first binary signal may (a) further include oneor more second bits having a second symbol when the value of the firstparameter is smaller than a maximum value, and (b) not include thesecond bits when the value of the first parameter is equal to themaximum value.

Accordingly, when the value of the first parameter is equal to themaximum value, the second bit (for example, 0) having the second symbolcan be omitted. Thus, the coding efficiency can be improved.

Furthermore, the moving picture decoding method according to an aspectof the present disclosure is a moving picture decoding method fordecoding a coded image, and includes: decoding at least a coded portionof a first binary signal through bypass arithmetic decoding using afixed probability, the first binary signal corresponding to a value of afirst parameter identifying a type of a sample offset process to beapplied to a reconstructed image obtained from the coded image; andconverting the decoded first binary signal into the value of the firstparameter.

Accordingly, at least the portion of the binary signal corresponding tothe value of the first parameter for identifying a type of the sampleoffset process can be decoded through the bypass arithmetic decoding.Thus, the number of loading and updating probability informationcorresponding to a context can be reduced more than that of decoding allthe binary signals by the context-adaptive arithmetic decoding.Furthermore, since the bypass arithmetic decoding does not requireupdating the probability information, arithmetic decoding can beperformed, in parallel, on bits included in a binary signal.

Furthermore, since the binary signal corresponding to the value of thefirst parameter conventionally has a bias in the symbol occurrenceprobability, it seems that the coding efficiency significantly decreaseswhen the binary signal is coded through the bypass arithmetic coding.However, the present disclosure reveals that the coding efficiency doesnot significantly decrease even when at least a portion of the binarysignal corresponding to the value of the first parameter is codedthrough the bypass arithmetic coding.

In other words, by decoding at least the coded portion of the binarysignal corresponding to the value of the first parameter for identifyinga type of the sample offset process through the bypass arithmeticcoding, processing can be accelerated or the processing load can bereduced while decrease in the coding efficiency can be suppressed.

For example, a coded first portion of the first binary signal may bedecoded through context-adaptive arithmetic decoding, and a coded secondportion of the first binary signal may be decoded through the bypassarithmetic decoding when the first binary signal includes the secondportion subsequent to the first portion. Accordingly, the coded firstportion of the binary signal can be decoded through the context-adaptivearithmetic decoding, and the coded second portion of the binary signalcan be decoded through the bypass arithmetic decoding. Thus, the codedbinary signal can be decoded by switching between the first portionhaving a larger bias in the symbol occurrence probability and the secondportion having a smaller bias in the symbol occurrence probability, andthe decrease in the coding efficiency can be further suppressed.

For example, the sample offset process may not be applied to thereconstructed image when the value of the first parameter is equal to apredetermined value, and the first portion of the first binary signalmay indicate whether or not the value of the first parameter is equal tothe predetermined value.

Accordingly, the first portion indicating whether or not the value ofthe first parameter is equal to the predetermined value can be decodedthrough the context-adaptive arithmetic decoding. In other words, thecoded first portion indicating whether or not the sample offset processis applied to the reconstructed image can be decoded through thecontext-adaptive arithmetic decoding. Since the portion indicatingwhether or not the sample offset process is applied to the reconstructedimage has a larger bias in the symbol occurrence probability, thedecrease in the coding efficiency can be further suppressed.

For example, the first portion of the first binary signal may becomposed of a first bit of the first binary signal, and the secondportion of the first binary signal may be composed of the remaining bitsof the first binary signal.

Accordingly, the coded first bit of the binary signal can be decodedthrough the context-adaptive arithmetic decoding, and the remaining bitsof the binary signal can be decoded through the bypass arithmeticdecoding.

For example, the moving picture decoding method may further include:decoding a coded first portion of a second binary signal correspondingto at least one of a value of a second parameter and a value of a thirdparameter, through the context-adaptive arithmetic decoding, the secondparameter identifying an intra prediction mode, the third parameteridentifying a candidate to be used for inter prediction from a list ofcandidates each including at least one motion vector; and decoding acoded second portion of the second binary signal through the bypassarithmetic decoding when the second binary signal includes the secondportion subsequent to the first portion, wherein a bit length of thefirst portion of the first binary signal may be identical to a bitlength of the first portion of the second binary signal.

Accordingly, since switching the arithmetic decoding between the firstparameter for identifying a type of a sample offset process and anotherparameter (second parameter or third parameter) can be standardizedbased on the bit position of the binary signal, the configuration of thedecoding apparatus can be simplified.

For example, the first binary signal may include one or more first bitshaving a first symbol when the value of the first parameter is largerthan 0, the number of the first bits being equal to the value of thefirst parameter, and the first binary signal may (a) further include oneor more second bits having a second symbol when the value of the firstparameter is smaller than a maximum value, and (b) not include thesecond bits when the value of the first parameter is equal to themaximum value.

Accordingly, when the value of the first parameter is equal to themaximum value, the second bit (for example, 0) having the second symbolcan be omitted. Thus, the coding efficiency can be improved.

These general or specific aspects may be implemented by a system, anapparatus, an integrated circuit, a computer program, or acomputer-readable recording medium, or by an arbitrary combination ofthe system, the apparatus, the integrated circuit, the computer program,and the recording medium.

Embodiments will be described will be described with reference to thedrawings.

Embodiments described hereinafter indicate specific or generic examplesof the present disclosure. The values, shapes, materials, constituentelements, positions and connections of the constituent elements, steps,and orders of the steps indicated in Embodiments are examples, and donot limit the claims. Furthermore, the constituent elements inEmbodiments that are not described in independent claims that describethe most generic concept of the present disclosure are described asarbitrary constituent elements.

Embodiment 1 <Overall Configuration>

FIG. 1 illustrates a configuration of a moving picture coding apparatus100 according to Embodiment 1. The moving picture coding apparatus 100codes an input picture per block.

As illustrated in FIG. 1, the moving picture coding apparatus 100includes a block partitioning unit 101, a prediction unit 102, asubtracting unit 103, a transform unit 104, an inverse transform unit105, an adding unit 106, an SAO processing unit 107, an SAO parametervariable length coding unit 108, a coefficient variable length codingunit 109, and a frame memory 110.

<Overall Operations>

Next, operations of the moving picture coding apparatus 100 with theconfiguration will be described. FIG. 2 shows processes performed by themoving picture coding apparatus 100 according to Embodiment 1.

(Step 101)

The block partitioning unit 101 partitions an input picture into blocks(for example, coding units). The block partitioning unit 101sequentially outputs the blocks to the subtracting unit 103 and theprediction unit 102 as blocks to be coded (input images). The blocks arevariable in size. The block partitioning unit 101 partitions the inputpicture into the blocks, using the features of an image. For example,the minimum size of the blocks is horizontal 4×vertical 4 pixels, andthe maximum size of the blocks is horizontal 32×vertical 32 pixels.

(Step 102)

The prediction unit 102 generates a prediction block, based on theblocks to be coded, and a reconstructed picture stored in the framememory 110 and corresponding to a picture that has already been coded.

(Step 103)

The subtracting unit 103 generates a residual block from each of theblocks to be coded and the prediction block.

(Step 104)

The transform unit 104 transforms the residual block into frequencycoefficients. Then, the transform unit 104 quantizes the frequencycoefficients.

(Step 105)

The inverse transform unit 105 inversely quantizes the quantizedfrequency coefficients. Then, the inverse transform unit 105 inverselytransforms the inversely-quantized frequency coefficients to reconstructthe residual block.

(Step 106)

The adding unit 106 adds the reconstructed residual block to theprediction block to generate a reconstructed block (reconstructedimage). The reconstructed block is sometimes referred to as “localdecoded block (local decoded image)”.

(Step 107)

The SAO processing unit 107 determines an SAO parameter. Furthermore,the SAO processing unit 107 adds an offset value to at least one pixelvalue (sample value) included in the reconstructed block, and stores aresult of the addition in the frame memory 110. In other words, the SAOprocessing unit 107 stores, in the frame memory 110, the reconstructedblock in which the SAO process has been performed.

More specifically, the SAO processing unit 107 classifies pixelsincluded in the reconstructed block into categories. Then, the SAOprocessing unit 107 adds, for each of the categories, an offset valuecorresponding to the category to a pixel value belonging to thecategory. There are plural methods for classifying pixels. In otherwords, one of the SAO processes of different types using the methods forclassifying pixels is adaptively applied. Thus, the SAO parameterincludes a parameter (sao_type_idx) for identifying a type of an SAOprocess. Furthermore, the SAO parameter also includes a parameter(sao_offset) indicating an offset value.

The SAO process does not always have to be performed.

(Step 108)

The SAO parameter variable length coding unit 108 performs variablelength coding (entropy coding) on the SAO parameter to output abitstream.

(Step 109)

The coefficient variable length coding unit 109 performs variable lengthcoding on the frequency coefficients to output a bitstream.

(Step 110)

The processes from Step 102 to Step 109 are repeated until coding allthe blocks in the input picture is completed.

The details of the SAO parameter variable length coding unit 108 and theoperation (Step 108) will be hereinafter described.

<Configuration of the SAO Parameter Variable Length Coding Unit>

FIG. 3 illustrates an internal configuration of the SAO parametervariable length coding unit 108 according to Embodiment 1. Asillustrated in FIG. 3, the SAO parameter variable length coding unit 108includes an sao_type_idx coding unit 121 and an sao_offset coding unit122.

<Operations (SAO Parameter Variable Length Coding)>

Next, operations of the SAO parameter variable length coding unit 108with the configuration will be described. FIG. 4 shows processesperformed by the SAO parameter variable length coding unit 108 accordingto Embodiment 1.

(Step 121)

The sao_type_idx coding unit 121 codes sao_type_idx for identifying atype of an SAO process.

(Step 122)

The sao_offset coding unit 122 codes sao_offset indicating an offsetvalue in the SAO process.

The details of the sao_type_idx coding unit 121 and the operation (StepS121) will be hereinafter described.

<Configuration of the Sao_Type_Idx Coding Unit>

FIG. 5 illustrates an internal configuration of the sao_type_idx codingunit 121 according to Embodiment 1. As illustrated in FIG. 5, thesao_type_idx coding unit 121 includes an sao_type_idx binarizing unit140 and an sao_type_idx arithmetic coding unit 150.

The sao_type_idx binarizing unit 140 converts a value of sao_type_idxinto a binary signal. As illustrated in FIG. 5, the sao_type_idxbinarizing unit 140 includes a bin setting unit 141 and a last bindetermining unit 142.

The sao_type_idx arithmetic coding unit 150 codes at least a portion ofthe binary signal through bypass arithmetic coding using a fixedprobability. As illustrated in FIG. 5, the sao_type_idx arithmeticcoding unit 150 includes an arithmetic coding switch unit 151, a firstcontext-adaptive arithmetic coding unit 152, a second context-adaptivearithmetic coding unit 153, and a bypass arithmetic coding unit 154.

<Operations (Sao_Type_Idx Coding)>

Next, details of the operations performed by the sao_type_idx codingunit 121 with the configuration will be described. FIG. 6 showsprocesses performed by the sao_type_idx coding unit 121 according toEmbodiment 1.

(Steps S141 to S144)

The bin setting unit 141 converts a value of sao_type_idx into a binarysignal (bin string). More specifically, the bin setting unit 141 sets 0or 1 to each bin included in the binary signal, using an index (binIdx)for identifying a position of the bin in the binary signal and the valueof sao_type_idx. Here, the value of sao_type_idx ranges between 0 and 5inclusive.

FIG. 7 is a table indicating a correspondence between the non-binarysignals (values of sao_type_idx) and the binary signals. As seen fromFIG. 7, the number of consecutive “1”s from the beginning of each binarysignal is equal to the value indicated by the non-binary signal.

In other words, when the value of sao_type_idx is larger than 0, thebinary signal includes one or more first bits having the first symbol“1”, where the number of the first bits is equal to the value ofsao_type_idx. Furthermore, the binary signal (a) includes one second bithaving the second symbol “0” when the value of sao_type_idx is smallerthan the maximum value of 5, and (b) does not include the second bithaving the second symbol “0” when the value of sao_type_idx is equal tothe maximum value.

Furthermore, the first value of a binIdx is 0, and the subsequent valuesare incremented by 1. The bin and the binIdx are output to thesao_type_idx arithmetic coding unit 150.

(Steps S145 to S149)

The arithmetic coding switch unit 151 switches a processing unit(constituent element) that performs arithmetic coding on a bin, based onthe value of the binIdx.

FIG. 8 is a table indicating a correspondence between binIdxs andcontexts. According to Embodiment 1, arithmetic coding is performed on abinary signal using two types of contexts (context 0 and context 1) asshown in the column of “Embodiment 1” in the table of FIG. 8.

More specifically, the arithmetic coding switch unit 151 switches to thefirst context-adaptive arithmetic coding unit 152 when the value of thebinIdx is equal to 0. Furthermore, the arithmetic coding switch unit 151switches to the second context-adaptive arithmetic coding unit 153 whenthe value of the binIdx is equal to 1. Furthermore, the arithmeticcoding switch unit 151 switches to the bypass arithmetic coding unit 154when the value of the binIdx is equal to neither 0 nor 1.

In other words, the first context-adaptive arithmetic coding unit 152performs arithmetic coding on a bin of a binIdx having 0, using thecontext 0. Furthermore, the second context-adaptive arithmetic codingunit 153 performs arithmetic coding on a bin of a binIdx having 1, usingthe context 1. Furthermore, the bypass arithmetic coding unit 154performs arithmetic coding on a bin of a binIdx having a value of 2 orhigher, using a fixed probability of 50% without using any context.

Here, a set of bins (bins identified by binIdxs having 0 and 1 accordingto Embodiment 1) coded through the context-adaptive arithmetic coding isreferred to as a first portion of a binary signal. Furthermore, a set ofbins (bins identified by binIdxs having a value of 2 or higher accordingto Embodiment 1) coded through the bypass arithmetic coding is referredto as a second portion of the binary signal.

In other words, the first portion of the binary signal is coded throughthe context-adaptive arithmetic coding according to Embodiment 1.Furthermore, when the binary signal includes the second portionsubsequent to the first portion, the second portion of the binary signalis coded through the bypass arithmetic coding.

(Steps S150 and S151)

The last bin determining unit 142 determines whether or not a bin has 0(first condition) and the binIdx has 4 (second condition). Here, when atleast one of the first condition and the second condition is satisfied,coding sao_type_idx is completed.

When none of the first condition and the second condition is satisfied,the last bin determining unit 142 updates the binIdx to a value obtainedby adding the value of the binIdx to 1. Then, the processes return toStep S142 to code the next bin.

According to Embodiment 1, when sao_type_idx has the maximum value of 5as shown in FIG. 7, Steps S150 and S151 can prevent 0 from being addedto the last of the binary signal.

<Advantages>

When sao_type_idx has the maximum value, the code amount can be reducedby preventing 0 from being added to the last of the binary signalaccording to Embodiment 1. In accordance with the HEVC standard in NPL1, 5 of sao_type_idx is converted into a binary signal represented by“111110”. Since sao_type_idx only takes values from 0 to 5, when thenumber of consecutive “1”s in a binary signal is five (“11111”), thedecoding apparatus recognizes sao_type_idx as 5. Thus, when sao_type_idxis equal to the maximum value of 5, the code amount can be reduced bypreventing 0 from being added to the last of the binary signal accordingto Embodiment 1.

Furthermore, determining the maximum number of bins included in thebinary signal of sao_type_idx as 5 increases error tolerance of thedecoding apparatus. More specifically, when an abnormal bitstream(binary signal in which consecutive “1”s are endless) is decoded,conventionally, the decoding processing does not end due to noappearance of 0. However, determining the maximum number of bins to 5enables completion of the decoding processing even when 0 does notappear in the binary signal.

Furthermore, performing the bypass arithmetic coding on bins that are ina latter half of the binary signal and obtained from the values ofsao_type_idx enables acceleration of the arithmetic coding or reductionin the load for the arithmetic coding. According to Embodiment 1, binsof a binIdx having a value of 2 or higher are coded not through thecontext-adaptive arithmetic coding but through the bypass arithmeticcoding. As described above, the bypass arithmetic coding does notrequire loading or updating a context, and the processing can be startedwithout waiting for completion of updating the context at the priorstages. Thus, the processing can be accelerated or the processing loadcan be reduced more than the context-adaptive arithmetic coding.

Furthermore, in accordance with the HEVC standard in NPL 1, thecontext-adaptive arithmetic coding is performed on a bin of a binIdxhaving a value of 1 or higher, using the same context. This is becausesymbol occurrence probabilities (probabilities of occurrence of 1) ofthe bin of the binIdx having a value of 1 or higher are almost the same,but are not equal to 50% and have a bias. In other words, when a binarysignal includes a bin whose binIdx is 1 or higher (value of sao_type_idxis 1 or higher), there are many cases where (a) the bin whose binIdx is1 has 0 and the binary signal does not include a bin whose binIdx is 2or higher (value of sao_type_idx is 1) and (b) no bin having 0 appearsup to the bin of the binIdx having a larger value (value of sao_type_idxis 4 or 5, etc).

However, the experiment in which arithmetic coding is performed on a binwhose binIdx is 2 or higher with a fixed symbol occurrence probabilityof 50% revealed that the coding efficiency is hardly degraded.Specifically, it revealed that the value of sao_type_idx often indicatesa medium value (2 or 3, etc) and the symbol occurrence probability ofthe bin whose binIdx is 2 or higher is closer to 50%. Thus, coding a binwhose binIdx is 2 or higher not through the context-adaptive arithmeticcoding but through the bypass arithmetic coding enables acceleratedprocessing or reduction in the processing load while suppressingdecrease in the coding efficiency.

Although the bypass arithmetic coding is performed on a bin whose binIdxis 2 or higher according to Embodiment 1, the processing is not limitedto such. For example, a bin whose binIdx is 1 or higher may be codedthrough the bypass arithmetic coding (Variation 1). For example, all thebins included in a binary signal may be coded through the bypassarithmetic coding (Variation 2).

As shown in FIG. 8, a bin whose binIdx is 1 or higher may be codedthrough the bypass arithmetic coding according to Variation 1. In otherwords, the first portion of a binary signal coded through thecontext-adaptive arithmetic coding is composed of the first bin of thebinary signal. Furthermore, the second portion of a binary signal codedthrough the bypass arithmetic coding is composed of the remaining binsof the binary signal. Furthermore, all the bins are coded through thebypass arithmetic coding according to Variation 2.

Hereinafter, the result of experiment according to Embodiment 1 andVariations 1 and 2 will be described. The test software in accordancewith the HEVC standard in which a method for performing bypassarithmetic coding on a bin whose binIdx is 2 or higher (Embodiment 1), amethod for performing bypass arithmetic coding on a bin whose binIdx is1 or higher (Variation 1), and a method for performing bypass arithmeticcoding on all of the bins (Variation 2) were adapted was used in theexperiment.

FIG. 9 is a table showing a result of the experiment in which the codingefficiencies between the conventional technique and Embodiment 1 andVariations 1 and 2 are compared. The experiment conditions follow thecommon experiment conditions of the HEVC standard organization. Thevalues of FIG. 9 are results on the first 49 frames in a test image. Thelarger the value is, the lower the coding efficiency is. The negativevalue indicates improvement in the coding efficiency in comparison withthe conventional technique (NPL1).

As illustrated in FIG. 9, the values range between −0.1 and 0.1% underall of the conditions, according to Embodiment 1 and Variation 1. Inother words, the coding efficiency hardly changes irrespective of theaccelerated processing by the bypass arithmetic coding according toEmbodiment 1 and Variation 1.

Furthermore, although the coding efficiency of Variation 2 is lower thanthose of Embodiment 1 and Variation 1, the values are within 1%.Furthermore, the coding efficiency hardly decreases under a condition AIin which all of the frames are intra-coded.

Thus, the coding method according to Variation 2 may be used when theaccelerated processing is prioritized even with slight reduction in thecoding efficiency and intra-coding is frequently applied. Otherwise,moving pictures may be coded in the coding methods according toEmbodiment 1 and Variation 1.

Here, a bin whose binIdx is 2 or lower may be coded through thecontext-adaptive arithmetic coding, and a bin whose binIdx is 3 orhigher may be coded through the bypass arithmetic coding.

Although Embodiment 1 uses sao_type_idx for identifying a type of an SAOprocess and sao_offset indicating a value of an SAO offset value as SAOparameters, the SAO parameters are not limited to such. The SAOparameters may include, for example, a parameter indicating auxiliaryinformation for classifying pixels. Furthermore, the SAO parameters mayinclude sao_offset_sign representing a sign bit (positive and negative)of sao_offset.

Furthermore, sao_type_idx may include information indicating noexecution of any SAO process. For example, when the value ofsao_type_idx is equal to 0, the SAO process does not always have to beperformed on a reconstructed block.

Furthermore, although the SAO parameter is coded per block according toEmbodiment 1, the coding is not limited to such. The SAO parameter maybe coded on a per unit smaller than the block. Conversely, the SAOparameter may be coded on a per unit obtained by concatenating blocks.Furthermore, the SAO parameter is not coded in a current block, butinstead, a value of an SAO parameter of another block may be copied andused.

Furthermore, although sao_type_idx takes values from 0 to 5 according toEmbodiment 1, the values are not limited to such. The maximum value ofsao_type_idx may be 6 or higher, or 4 or lower.

For example, the following will describe a case where the maximum valueof sao_type_idx is 2. In other words, the case where the number of typesof SAO processes is three.

FIG. 10 is a table indicating a correspondence between non-binarysignals (sao_type_idx) and binary signals according to Variation 3.Furthermore, FIG. 11 is a table indicating a correspondence betweenbinIdxs and a context according to Variation 3.

For example, when the value of sao_type_idx is equal to 0, the SAOprocess is not applied to a reconstructed block according to Variation3. Furthermore, when the value of sao_type_idx is equal to 1, a firstSAO process is applied to the reconstructed block. Furthermore, when thevalue of sao_type_idx is equal to 2, a second SAO process is applied tothe reconstructed block.

The first SAO process is, for example, a band offset process.Furthermore, the second SAO process is, for example, an edge offsetprocess. In the edge offset process, a category to which each of pixelsbelongs is determined, based on a difference between a pixel value ofthe pixel and a pixel value of a pixel adjacent to the pixel.Furthermore, in the band offset process, a range of possible pixelvalues is divided into bands, and a category to which each of the pixelsbelongs is determined based on the band to which the pixel value of thepixel belongs. Since NPL1 and others disclose the details of the edgeoffset process and the band offset process, the details are omittedherein.

As shown in FIGS. 10 and 11, the first bin (binIdx=0, the first portion)of a binary signal is coded through the context-adaptive arithmeticcoding according to Variation 3. Furthermore, the remaining bins(binIdx=1, the second portion) of the binary signal are coded throughthe bypass arithmetic coding.

Here, only when the value of sao_type_idx is equal to 0, the first binhas 0. Otherwise, the first bin has 1. In other words, the first portionof a binary signal indicates whether or not the value of sao_type_idx isequal to a predetermined value of 0. In other words, the first portionof the binary signal indicates whether or not the SAO process is appliedto a reconstructed block. As such, a portion indicating whether or notthe SAO process is applied to a reconstructed block is coded through thecontext-adaptive arithmetic coding, and (ii) the other portions arecoded through the bypass arithmetic coding. These processes enableaccelerated processing or reduction in the processing load whilesuppressing decrease in the coding efficiency.

The coding methods according to Embodiment 1 and Variations 1 to 3 maybe applied not only to sao_type_idx but to the other syntaxes that areadded to a bitstream. Accordingly, the processing performed by avariable length coding unit can be standardized.

The bypass arithmetic coding may be performed on a second portion of abinary signal corresponding to, for example, sao_offset indicating anSAO offset value, ref_idx indicating an index of a reference image,merge_idx for identifying a candidate to be used in inter predictionfrom a list of candidates each including at least one motion vector, ormpm_idx or intra_chroma_pred_mode for identifying an intra predictionmode. Since NPL1 discloses sao_offset, ref_idx, merge_idx, mpm_idx, andintra_chroma_pred_mode, the details are omitted herein.

In other words, the bit length of the first portion of the first binarysignal may be identical to the bit length of the first portion of thesecond binary signal. Here, the first binary signal is a binary signalobtained by binarizing a value of a parameter (sao_type_idx) foridentifying a type of a sample offset process. Furthermore, the secondbinary signal is a binary signal obtained by binarizing at least one of(i) a parameter (for example, intra_chroma_pred_mode) for identifying anintra prediction mode and (ii) a parameter (for example, merge_idx) foridentifying a candidate to be used in inter prediction from a list ofcandidates each including at least one motion vector.

As such, standardizing, for sao_type_idx and the other syntaxes, aportion on which the bypass arithmetic coding is performed enables notonly the accelerated processing, but also the simplification of theconfiguration of an apparatus with the common use of a variable lengthcoding unit.

Furthermore, although the minimum size of the blocks is 4×4 pixels andthe maximum size of the blocks is 32×32 pixels, the sizes are notlimited to such. Furthermore, the size of the blocks does not have to bevariable and may be fixed.

Furthermore, the sample offset process is not limited to the SAO processdescribed in NPL1. In other words, the sample offset process may be anyprocess as long as a sample value (pixel value) of a reconstructed imageis offset.

Embodiment 2

Next, Embodiment 2 will be described. Embodiment 2 will describedecoding an image coded in the moving picture coding method according toEmbodiment 1. In particular, Embodiment 2 will describe performingarithmetic decoding on a parameter that is coded according to Embodiment1 and is for identifying a type of a sample offset process.

<Overall Configuration>

FIG. 12 illustrates a configuration of a moving picture decodingapparatus 200 according to Embodiment 2. The moving picture decodingapparatus 200 decodes a coded picture per block.

As illustrated in FIG. 12, the moving picture decoding apparatus 200includes an SAO parameter variable length decoding unit 201, acoefficient variable length decoding unit 202, an inverse transform unit203, a prediction unit 204, an adding unit 205, an SAO processing unit206, a block combining unit 207, and a frame memory 208.

<Overall Operations>

Next, operations of the moving picture decoding apparatus 200 with theconfiguration will be described. FIG. 13 shows processes performed bythe moving picture decoding apparatus 200 according to Embodiment 2.

(Step 201)

The SAO parameter variable length decoding unit 201 performs variablelength decoding (entropy decoding) on a coded SAO parameter included ina bitstream.

(Step 202)

The coefficient variable length decoding unit 202 performs variablelength decoding on coded frequency coefficients included in thebitstream to output the frequency coefficients to the inverse transformunit 203.

(Step 203)

The inverse transform unit 203 inversely transforms the frequencycoefficients into pixel data to generate a residual block.

(Step 204)

The prediction unit 204 generates a prediction block, based on a picturethat is stored in the frame memory 208 and has already been decoded.

(Step 205)

The adding unit 205 adds the residual block to the prediction block togenerate a reconstructed block.

(Step 206)

The SAO processing unit 206 classifies pixels included in thereconstructed block into categories, according to the SAO parameter.Then, the SAO processing unit 206 adds a corresponding offset value foreach of the categories. In other words, the SAO processing unit 206applies the SAO process to the reconstructed block using the SAOparameter. Here, the SAO parameters include a parameter (sao_type_idx)for identifying a type of an SAO process and a parameter (sao_offset)indicating an offset value.

The SAO process does not always have to be performed. For example, whenthe value of sao_type_idx is equal to a predetermined value, the SAOprocess does not have to be performed.

(Step 207)

The processes from Steps S201 to S206 are repeated until processing onall the blocks included in the picture to be decoded is completed.

(Step 208)

The block combining unit 207 combines the bocks to generate a decodedpicture. Furthermore, the block combining unit 207 stores the decodedpicture in the frame memory 208.

The details of the SAO parameter variable length decoding unit 201 andthe process (Step 201) will be hereinafter described.

<Configuration of the SAO Parameter Variable Length Decoding Unit>

FIG. 14 illustrates an internal configuration of the SAO parametervariable length decoding unit 201 according to Embodiment 2. Asillustrated in FIG. 14, the SAO parameter decoding unit 201 includes ansao_type_idx decoding unit 221 and an sao_offset decoding unit 222.

<Operations (SAO Parameter Variable Length Decoding)>

Next, operations of the SAO parameter variable length decoding unit 201with the configuration will be described. FIG. 15 shows processesperformed by the SAO parameter variable length decoding unit 201according to Embodiment 2.

(Step 221)

The sao_type_idx decoding unit 221 decodes coded sao_type_idx.

(Step 222)

The sao_offset decoding unit 222 decodes coded sao_offset.

The details of the sao_type_idx decoding unit 221 and the operation(Step S221) will be hereinafter described.

<Configuration of the Sao_Type_Idx Decoding Unit>

FIG. 16 illustrates an internal configuration of the sao_type_idxdecoding unit 221 according to Embodiment 2. As illustrated in FIG. 16,the sao_type_idx decoding unit 221 includes an sao_type_idx arithmeticdecoding unit 240 and an sao_type_idx inverse binarizing unit 250.

The sao_type_idx arithmetic decoding unit 240 decodes at least a codedportion of a binary signal corresponding to sao_type_idx for identifyinga type of an SAO process to be applied to a reconstructed block, throughbypass arithmetic decoding. As illustrated in FIG. 16, the sao_type_idxarithmetic decoding unit 240 includes an arithmetic decoding switch unit241, a first context-adaptive arithmetic decoding unit 242, a secondcontext-adaptive arithmetic decoding unit 243, and a bypass arithmeticdecoding unit 244.

The sao_type_idx inverse binarizing unit 250 converts the decoded binarysignal into the value of sao_type_idx. As illustrated in FIG. 16, thesao_type_idx inverse binarizing unit 250 includes a last bin determiningunit 251 and an sao_type_idx setting unit 252.

<Operations (Sao_Type_Idx Decoding)>

Next, details of the operations performed by the sao_type_idx decodingunit 221 with the configuration will be described. FIG. 17 showsprocesses performed by the sao_type_idx decoding unit 221 according toEmbodiment 2.

(Step S241 to S246)

The arithmetic decoding switch unit 241 determines a value of a binIdxof a bin to be processed. Then, the arithmetic decoding switch unit 241switches a processing unit (constituent element) that performsarithmetic decoding on a coded bin, based on the determined value of thebinIdx. More specifically, the arithmetic decoding switch unit 241switches to the first context-adaptive arithmetic decoding unit 242 whenthe value of the binIdx is equal to 0. More specifically, the arithmeticdecoding switch unit 241 switches to the second context-adaptivearithmetic decoding unit 243 when the value of the binIdx is equal to 1.Furthermore, the arithmetic decoding switch unit 241 switches to thebypass arithmetic decoding unit 244 when the value of the binIdx isequal to neither 0 nor 1.

In other words, the first context-adaptive arithmetic decoding unit 242performs arithmetic decoding on a coded bin of the binIdx having 0,using the context 0. Furthermore, the second context-adaptive arithmeticdecoding unit 243 performs arithmetic decoding on a coded bin of thebinIdx having 1, using the context 1. Furthermore, the bypass arithmeticcoding unit 244 performs arithmetic decoding on a bin of the binIdxhaving a value of 2 or higher, using a fixed probability of 50% withoutusing any context.

Here, a set of bins (bins identified by binIdxs having 0 and 1 accordingto Embodiment 2) coded through the context-adaptive arithmetic coding isreferred to as a first portion of a binary signal. Furthermore, a set ofbins (bins identified by binIdxs each having a value of 2 or higheraccording to Embodiment 2) coded through the bypass arithmetic coding isreferred to as a second portion of the binary signal.

In other words, the coded first portion of the binary signal is decodedthrough the context-adaptive arithmetic decoding according to Embodiment2. Furthermore, when the binary signal includes the second portionsubsequent to the first portion, the coded second portion of the binarysignal is decoded through the bypass arithmetic decoding.

(Steps S247 and S248)

When the bin resulting from the arithmetic decoding is 0 or the value ofthe binIdx is equal to 4, the last bin determining unit 251 completesthe arithmetic decoding on the coded bin, and the processes proceed toStep S249. When the value of the bin is equal to 1 and the value of thebinIdx is 3 or lower, the last bin determining unit 251 adds 1 to thevalue of the binIdx, and the processes proceed to Step S242.

(Steps S249 to S251)

The sao_type_idx setting unit 252 sets the value of the binIdx tosao_type_idx. Furthermore, when the value of the binIdx is equal to 4and the value of the bin is 1, the sao_type_idx setting unit 252 sets 5to sao_type_idx. With Steps S249 to S251, a binary signal can beconverted into 5 that is the value of sao_type_idx even when no 0 is atthe end of the binary signal. The correspondence between the non-binarysignals and the binary signals is the same as shown in FIG. 7 accordingto Embodiment 1.

<Advantages>

According to Embodiment 2, sao_type_idx coded in Embodiment 1 can bedecoded. In other words, at least a coded portion of a binary signalcorresponding to a value of sao_type_idx can be decoded through thebypass arithmetic decoding. Thus, the same advantages as those accordingto Embodiment 1 can be produced. For example, processing can beaccelerated or the processing load can be reduced while decrease in thecoding efficiency can be suppressed.

Thus, the same variations as those according to Embodiment 1 can beapplied to Embodiment 2. In other words, the coded sao_type_idx may bedecoded as shown in FIGS. 8, 10, and 11 according to Variations 1 to 3.

Furthermore, the bypass arithmetic decoding may be performed on thecoded second portion of a binary signal corresponding to, for example,sao_offset indicating an SAO offset value, ref_idx indicating an indexof a reference image, merge_idx for identifying a candidate to be usedin inter prediction from a list of candidates each including at leastone motion vector, or mpm_idx or intra_chroma_pred_mode for identifyingan intra prediction mode, also in Embodiment 2. In other words, the bitlength of the first portion of the first binary signal may be identicalto the bit length of the first portion of the second binary signal.

Although the moving picture coding apparatus and the moving picturedecoding apparatus according to one or more aspects of the presentdisclosure are described based on Embodiments 1 and 2, the presentdisclosure is not limited to these Embodiments. Without departing fromthe scope of the present disclosure, the aspects of the presentdisclosure may include an embodiment with some modifications onEmbodiments that are conceived by a person skilled in the art, andanother embodiment obtained through combinations of the constituentelements of different Embodiments.

For example, the moving picture coding apparatus neither have to includea part of the constituent elements in FIG. 1 nor perform a part of Stepsin FIG. 2. Furthermore, the moving picture decoding apparatus neitherhave to include a part of the constituent elements in FIG. 12 norperform a part of Steps in FIG. 13. One of the examples of such movingpicture coding apparatus and moving picture decoding apparatus will bedescribed hereinafter.

FIG. 18A illustrates a configuration of a moving picture codingapparatus 300 according to another Embodiment. Furthermore, FIG. 18Bshows processes performed by the moving picture coding apparatus 300according to the other Embodiment.

The moving picture coding apparatus 300 includes a binarizing unit(binarizer) 301 and an arithmetic coding unit (arithmetic coder) 302.

The binarizing unit 301 corresponds to the sao_type_idx binarizing unit140 according to Embodiment 1. The binarizing unit 301 converts a valueof a parameter for identifying a type of a sample offset process into abinary signal (S301).

The arithmetic coding unit 302 corresponds to the sao_type_idxarithmetic coding unit 150 according to Embodiment 1. The arithmeticcoding unit 302 codes at least a portion of a binary signal throughbypass arithmetic coding using a fixed probability (S302).

Since the moving picture coding apparatus 300 can code at least aportion of a binary signal corresponding to a parameter for identifyinga type of a sample offset process, through bypass arithmetic coding,processing can be accelerated or the processing load can be reducedwhile decrease in the coding efficiency can be suppressed.

FIG. 19A illustrates a configuration of a moving picture decodingapparatus 400 according to the other Embodiment. Furthermore, FIG. 19Bshows processes performed by the moving picture decoding apparatus 400according to the other Embodiment.

The moving picture decoding apparatus 400 includes an arithmeticdecoding unit (arithmetic decoder) 401 and an inverse binarizing unit(inverse binarizer) 402.

The arithmetic decoding unit 401 corresponds to the sao_type_idxarithmetic decoding unit 240 according to Embodiment 2. The arithmeticdecoding unit 401 decodes at least a coded portion of a binary signalcorresponding to a parameter for identifying a type of a sample offsetprocess to be applied to a reconstructed block obtained from a codedimage, through bypass arithmetic decoding (S401).

The inverse binarizing unit 402 corresponds to the sao_type_idx inversebinarizing unit 250 according to Embodiment 2. The inverse binarizingunit 402 converts the decoded binary signal into a value of theparameter for identifying the type of the sample offset process (S402).

Since the moving picture decoding apparatus 400 can decode at least acoded portion of a binary signal corresponding to a parameter foridentifying a type of a sample offset process, through bypass arithmeticdecoding, processing can be accelerated or the processing load can bereduced while decrease in the coding efficiency can be suppressed.

In general, in each of Embodiments, each of the functional blocks may beimplemented by, for example, an MPU and a memory. Furthermore, ingeneral, the processing by each of the functional blocks may beimplemented by software (a program), and such software is recorded on arecording medium such as a ROM. In addition, such software may bedistributed by, for example, downloading and recording it on recordingmedia such as CD-ROMs. Each of the functional blocks may be implementedby hardware (a dedicated circuit).

The processing described in each of Embodiments may be performed ascentralized processing by a single apparatus (system) or may beperformed as decentralized processing by a plurality of apparatuses.Here, the program may be executed by one or more computers. In otherwords, any one of the centralized processing and the decentralizedprocessing may be performed.

Furthermore, each of the constituent elements according to each ofEmbodiments 1 and 2 may be implemented by dedicated hardware or byexecuting a software program appropriate for the constituent element.Each of the constituent elements may be implemented by a programexecuting unit, such as a central processing unit (CPU) and a processor,reading and executing the software program recorded on a recordingmedium, such as a hard disk or a semiconductor memory.

Specifically, each of the moving picture coding apparatus and the movingpicture decoding apparatus includes control circuitry and storageelectrically connected to (capable of accessing from) the controlcircuitry. The control circuitry may include at least one of thededicated hardware and the program executing unit. Furthermore, when thecontrol circuitry includes the program executing unit, the storage maystore the software program executed by the program executing unit.

Here, the software that implements the moving picture coding apparatusand the moving picture decoding apparatus according to each ofEmbodiments 1 and 2 is the following program.

Specifically, the program causes a computer to execute a moving picturecoding method for coding an input image, the method including:converting a value of a first parameter into a first binary signal, thefirst parameter identifying a type of a sample offset process to beapplied to a reconstructed image corresponding to the input image; andcoding at least a portion of the first binary signal through bypassarithmetic coding using a fixed probability.

Furthermore, the program causes a computer to execute a moving picturedecoding method for decoding a coded image, the method including:decoding at least a coded portion of a first binary signal throughbypass arithmetic decoding using a fixed probability, the first binarysignal corresponding to a value of a first parameter identifying a typeof a sample offset process to be applied to a reconstructed imageobtained from the coded image; and converting the decoded first binarysignal into the value of the first parameter.

Embodiment 3

An independent computer system can easily perform processing describedin each of Embodiments by recording, in a recording medium, a programfor implementing the structure of the moving picture coding method(image coding method) or the moving picture decoding method (imagedecoding method) according to Embodiment. The recording medium may beany as long as the program can be recorded thereon, such as a magneticdisk, an optical disk, an optical magnetic disk, an IC card, and asemiconductor memory.

Hereinafter, applications of the moving picture coding method (imagecoding method) and the moving picture decoding method (image decodingmethod) according to each of Embodiments, and a system using suchapplications will be described. The system features including an imagecoding apparatus using the image coding method, and an image coding anddecoding apparatus including an image decoding apparatus using the imagedecoding method. The other configurations of the system can beappropriately changed depending on a case.

FIG. 20 illustrates an overall configuration of a content providingsystem ex100 for implementing content distribution services. The areafor providing communication services is divided into cells of desiredsize, and base stations ex106 to ex110 which are fixed wireless stationsare placed in each of the cells.

The content providing system ex100 is connected to devices, such as acomputer ex111, a personal digital assistant (PDA) ex112, a cameraex113, a cellular phone ex114, and a game machine ex115, via an Internetex101, an Internet service provider ex102, a telephone network ex104, aswell as the base stations ex106 to ex110.

However, the configuration of the content providing system ex100 is notlimited to the configuration shown in FIG. 20, and a combination inwhich any of the elements are connected is acceptable. In addition, eachof the devices may be directly connected to the telephone network ex104,rather than via the base stations ex106 to ex110 which are the fixedwireless stations. Furthermore, the devices may be interconnected toeach other via a short distance wireless communication and others.

The camera ex113, such as a digital video camera, is capable ofcapturing moving images. A camera ex116, such as a digital video camera,is capable of capturing both still images and moving images.Furthermore, the cellular phone ex114 may be the one that meets any ofthe standards such as Global System for Mobile Communications (GSM),Code Division Multiple Access (CDMA), Wideband-Code Division MultipleAccess (W-CDMA), Long Term Evolution (LTE), and High Speed Packet Access(HSPA). Alternatively, the cellular phone ex114 may be a PersonalHandyphone System (PHS).

In the content providing system ex100, a streaming server ex103 isconnected to the camera ex113 and others via the telephone network ex104and the base station ex109, which enables distribution of a live showand others. For such a distribution, a content (for example, video of amusic live show) captured by the user using the camera ex113 is coded asdescribed above in each of Embodiments, and the coded content istransmitted to the streaming server ex103. On the other hand, thestreaming server ex103 carries out stream distribution of the receivedcontent data to the clients upon their requests. The clients include thecomputer ex111, the PDA ex112, the camera ex113, the cellular phoneex114, and the game machine ex115 that are capable of decoding theabove-mentioned coded data. Each of the devices that have received thedistributed data decodes and reproduces the coded data (that is,functions as the image decoding apparatus according to an aspect of thepresent disclosure).

The captured data may be coded by the camera ex113 or the streamingserver ex103 that transmits the data, or the coding processes may beshared between the camera ex113 and the streaming server ex103.Similarly, the distributed data may be decoded by the clients or thestreaming server ex103, or the decoding processes may be shared betweenthe clients and the streaming server ex103. Furthermore, the data of thestill images and the moving images captured by not only the camera ex113but also the camera ex116 may be transmitted to the streaming serverex103 through the computer ex111. The coding processes may be performedby the camera ex116, the computer ex111, or the streaming server ex103,or shared among them.

Furthermore, generally, the computer ex111 and an LSI ex500 included ineach of the devices perform such encoding and decoding processes. TheLSI ex500 may be configured of a single chip or a plurality of chips.Software for encoding and decoding moving pictures may be integratedinto some type of a recording medium (such as a CD-ROM, a flexible disk,a hard disk) that is readable by the computer ex111 and others, and theencoding and decoding processes may be performed using the software.Furthermore, when the cellular phone ex114 is equipped with a camera,the video data obtained by the camera may be transmitted. The video datais data coded by the LSI ex500 included in the cellular phone ex114.

Furthermore, the streaming server ex103 may be composed of servers andcomputers, and may decentralize data and process the decentralized data,record, or distribute data.

As described above, the clients can receive and reproduce the coded datain the content providing system ex100. In other words, the clients canreceive and decode information transmitted by the user, and reproducethe decoded data in real time in the content providing system ex100, sothat the user who does not have any particular right and equipment canimplement personal broadcasting.

The present disclosure is not limited to the above-mentioned contentproviding system ex100, and at least either the moving picture codingapparatus (image coding apparatus) or the moving picture decodingapparatus (image decoding apparatus) described in each of Embodimentscan be incorporated into a digital broadcasting system ex200 as shown inFIG. 21. More specifically, a broadcast station ex201 communicates ortransmits, via radio waves to a broadcast satellite ex202, multiplexeddata obtained by multiplexing the audio data onto the video data. Thevideo data is data coded according to the moving picture coding methoddescribed in each of Embodiments (that is, data coded by the imagecoding apparatus according to the aspect of the present disclosure).Upon receipt of the video data, the broadcast satellite ex202 transmitsradio waves for broadcasting. Then, a home-use antenna ex204 capable ofreceiving a satellite broadcast receives the radio waves. A device, suchas a television (receiver) ex300 and a set top box (STB) ex217, decodesthe received multiplexed data and reproduces the data (that is,functions as the image decoding apparatus according to the aspect of thepresent disclosure).

Furthermore, a reader/recorder ex218 that (i) reads and decodes themultiplexed data recorded on a recording media ex215, such as a DVD anda BD, or (ii) codes video signals in the recording medium ex215, and insome cases, writes data obtained by multiplexing an audio signal on thecoded data can include the moving picture decoding apparatus or themoving picture coding apparatus as shown in each of Embodiments. In thiscase, the reproduced video signals are displayed on the monitor ex219,and another apparatus or system can reproduce the video signals, usingthe recording medium ex215 on which the multiplexed data is recorded.Furthermore, it is also possible to implement the moving picturedecoding apparatus in the set top box ex217 connected to the cable ex203for a cable television or the antenna ex204 for satellite and/orterrestrial broadcasting, so as to display the video signals on themonitor ex219 of the television ex300. The moving picture decodingapparatus may be included not in the set top box but in the televisionex300.

FIG. 22 illustrates the television (receiver) ex300 that uses the movingpicture coding method and the moving picture decoding method describedin each of Embodiments. The television ex300 includes: a tuner ex301that obtains or provides multiplexed data obtained by multiplexing theaudio data and the video data through the antenna ex204 or the cableex203, etc. that receives a broadcast; a modulation/demodulation unitex302 that demodulates the received multiplexed data or modulates datainto multiplexed data to be supplied outside; and amultiplexing/demultiplexing unit ex303 that demultiplexes the modulatedmultiplexed data into video data and audio data, or multiplexes thevideo data and audio data coded by the signal processing unit ex306 intodata.

Furthermore, the television ex300 further includes: a signal processingunit ex306 including an audio signal processing unit ex304 and a videosignal processing unit ex305 that decode audio data and video data andcode audio data and video data, respectively (which function as theimage coding apparatus or the image decoding apparatus according to theaspect of the present disclosure); a speaker ex307 that provides thedecoded audio signal; and an output unit ex309 including a display unitex308 that displays the decoded video signal, such as a display.Furthermore, the television ex300 includes an interface unit ex317including an operation input unit ex312 that receives an input of a useroperation. Furthermore, the television ex300 includes a control unitex310 that controls overall each constituent element of the televisionex300, and a power supply circuit unit ex311 that supplies power to eachof the elements. Other than the operation input unit ex312, theinterface unit ex317 may include: a bridge ex313 that is connected to anexternal device, such as the reader/recorder ex218; a slot unit ex314for enabling attachment of the recording medium ex216, such as an SDcard; a driver ex315 to be connected to an external recording medium,such as a hard disk; and a modem ex316 to be connected to a telephonenetwork. Here, the recording medium ex216 can electrically recordinformation using a non-volatile/volatile semiconductor memory elementfor storage. The constituent elements of the television ex300 areconnected to one another through a synchronous bus.

First, a configuration in which the television ex300 decodes themultiplexed data obtained from outside through the antenna ex204 andothers and reproduces the decoded data will be described. In thetelevision ex300, upon receipt of a user operation from a remotecontroller ex220 and others, the multiplexing/demultiplexing unit ex303demultiplexes the multiplexed data demodulated by themodulation/demodulation unit ex302, under control of the control unitex310 including a CPU. Furthermore, the audio signal processing unitex304 decodes the demultiplexed audio data, and the video signalprocessing unit ex305 decodes the demultiplexed video data, using thedecoding method described in each of Embodiments, in the televisionex300. The output unit ex309 provides the decoded video signal and audiosignal outside. When the output unit ex309 provides the video signal andthe audio signal, the signals may be temporarily stored in buffers ex318and ex319, and others so that the signals are reproduced insynchronization with each other. Furthermore, the television ex300 mayread the multiplexed data not through a broadcast and others but fromthe recording media ex215 and ex216, such as a magnetic disk, an opticaldisc, and an SD card. Next, a configuration in which the televisionex300 codes an audio signal and a video signal, and transmits the dataoutside or writes the data on a recording medium will be described. Inthe television ex300, upon receipt of a user operation from the remotecontroller ex220 and others, the audio signal processing unit ex304codes an audio signal, and the video signal processing unit ex305 codesa video signal, under control of the control unit ex310 using the codingmethod as described in each of Embodiments. Themultiplexing/demultiplexing unit ex303 multiplexes the coded videosignal and audio signal, and provides the resulting signal outside. Whenthe multiplexing/demultiplexing unit ex303 multiplexes the video signaland the audio signal, the signals may be temporarily stored in buffersex320 and ex321, and others so that the signals are reproduced insynchronization with each other. Here, the buffers ex318 to ex321 may beplural as illustrated, or at least one buffer may be shared in thetelevision ex300. Furthermore, data may be stored in a buffer other thanthe buffers ex318 to ex321 so that the system overflow and underflow maybe avoided between the modulation/demodulation unit ex302 and themultiplexing/demultiplexing unit ex303, for example.

Furthermore, the television ex300 may include a configuration forreceiving an AV input from a microphone or a camera other than theconfiguration for obtaining audio and video data from a broadcast or arecording medium, and may code the obtained data. Although thetelevision ex300 can code, multiplex, and provide outside data in thedescription, it may be not capable of performing all the processes butcapable of only one of receiving, decoding, and providing outside data.

Furthermore, when the reader/recorder ex218 reads or writes themultiplexed data from or in a recording medium, one of the televisionex300 and the reader/recorder ex218 may decode or code the multiplexeddata, and the television ex300 and the reader/recorder ex218 may sharethe decoding or encoding.

As an example, FIG. 23 illustrates a configuration of an informationreproducing/recording unit ex400 when data is read or written from or inan optical disc. The information reproducing/recording unit ex400includes constituent elements ex401 to ex407 to be describedhereinafter. The optical head ex401 irradiates a laser spot on arecording surface of the recording medium ex215 that is an optical discto write information, and detects reflected light from the recordingsurface of the recording medium ex215 to read the information. Themodulation recording unit ex402 electrically drives a semiconductorlaser included in the optical head ex401, and modulates the laser lightaccording to recorded data. The reproduction demodulating unit ex403amplifies a reproduction signal obtained by electrically detecting thereflected light from the recording surface using a photo detectorincluded in the optical head ex401, and demodulates the reproductionsignal by separating a signal component recorded on the recording mediumex215 to reproduce the necessary information. The buffer ex404temporarily holds the information to be recorded on the recording mediumex215 and the information reproduced from the recording medium ex215. Adisk motor ex405 rotates the recording medium ex215. A servo controlunit ex406 moves the optical head ex401 to a predetermined informationtrack while controlling the rotation drive of the disk motor ex405 so asto follow the laser spot. The system control unit ex407 controls overallthe information reproducing/recording unit ex400. The reading andwriting processes can be implemented by the system control unit ex407using various information stored in the buffer ex404 and generating andadding new information as necessary, and by the modulation recordingunit ex402, the reproduction demodulating unit ex403, and the servocontrol unit ex406 that record and reproduce information through theoptical head ex401 while being operated in a coordinated manner. Thesystem control unit ex407 includes, for example, a microprocessor, andexecutes processing by causing a computer to execute a program for readand write.

Although the optical head ex401 irradiates a laser spot in thedescription, it may perform high-density recording using near fieldlight.

FIG. 24 schematically illustrates the recording medium ex215 that is theoptical disc. On the recording surface of the recording medium ex215,guide grooves are spirally formed, and an information track ex230records, in advance, address information indicating an absolute positionon the disk according to change in a shape of the guide grooves. Theaddress information includes information for determining positions ofrecording blocks ex231 that are a unit for recording data. An apparatusthat records and reproduces data reproduces the information track ex230and reads the address information so as to determine the positions ofthe recording blocks. Furthermore, the recording medium ex215 includes adata recording area ex233, an inner circumference area ex232, and anouter circumference area ex234. The data recording area ex233 is an areafor use in recording the user data. The inner circumference area ex232and the outer circumference area ex234 that are inside and outside ofthe data recording area ex233, respectively are for specific use exceptfor recording the user data. The information reproducing/recording unit400 reads and writes coded audio data, coded video data, or multiplexeddata obtained by multiplexing the coded audio data and the coded videodata, from and on the data recording area ex233 of the recording mediumex215.

Although an optical disc having a layer, such as a DVD and a BD isdescribed as an example in the description, the optical disc is notlimited to such, and may be an optical disc having a multilayerstructure and capable of being recorded on a part other than thesurface. Furthermore, the optical disc may have a structure formultidimensional recording/reproduction, such as recording ofinformation using light of colors with different wavelengths in the sameportion of the optical disc and recording information having differentlayers from various angles.

Furthermore, the car ex210 having the antenna ex205 can receive datafrom the satellite ex202 and others, and reproduce video on the displaydevice such as the car navigation system ex211 set in the car ex210, ina digital broadcasting system ex200. Here, a configuration of the carnavigation system ex211 will be the one for example, including a GPSreceiving unit in the configuration illustrated in FIG. 22. The samewill be true for the configuration of the computer ex111, the cellularphone ex114, and others.

FIG. 25A illustrates the cellular phone ex114 that uses the movingpicture coding method and the moving picture decoding method describedin each of Embodiments. The cellular phone ex114 includes: an antennaex350 for transmitting and receiving radio waves through the basestation ex110; a camera unit ex365 capable of capturing moving and stillimages; and a display unit ex358 such as a liquid crystal display fordisplaying the data such as decoded video captured by the camera unitex365 or received by the antenna ex350. The cellular phone ex114 furtherincludes: a main body unit including a set of operation keys ex366; anaudio output unit ex357 such as a speaker for output of audio; an audioinput unit ex356 such as a microphone for input of audio; a memory unitex367 for storing captured video or still pictures, recorded audio,coded or decoded data of the received video, the still images, e-mails,or others; and a slot unit ex364 that is an interface unit for arecording medium that stores data in the same manner as the memory unitex367.

Next, an example of a configuration of the cellular phone ex114 will bedescribed with reference to FIG. 25B. In the cellular phone ex114, amain control unit ex360 designed to control overall each unit of themain body including the display unit ex358 as well as the operation keysex366 is connected mutually, via a synchronous bus ex370, to a powersupply circuit unit ex361, an operation input control unit ex362, avideo signal processing unit ex355, a camera interface unit ex363, aliquid crystal display (LCD) control unit ex359, amodulation/demodulation unit ex352, a multiplexing/demultiplexing unitex353, an audio signal processing unit ex354, the slot unit ex364, andthe memory unit ex367.

When a call-end key or a power key is turned ON by a user's operation,the power supply circuit unit ex361 supplies the respective units withpower from a battery pack so as to activate the cell phone ex114.

In the cellular phone ex114, the audio signal processing unit ex354converts the audio signals collected by the audio input unit ex356 invoice conversation mode into digital audio signals under the control ofthe main control unit ex360 including a CPU, ROM, and RAM. Then, themodulation/demodulation unit ex352 performs spread spectrum processingon the digital audio signals, and the transmitting and receiving unitex351 performs digital-to-analog conversion and frequency conversion onthe data, so as to transmit the resulting data via the antenna ex350.Then, the modulation/demodulation unit ex352 performs inverse spreadspectrum processing on the data, and the audio signal processing unitex354 converts it into analog audio signals, so as to output them viathe audio output unit ex357.

Furthermore, when an e-mail in data communication mode is transmitted,text data of the e-mail inputted by operating the operation keys ex366and others of the main body is sent out to the main control unit ex360via the operation input control unit ex362. The main control unit ex360causes the modulation/demodulation unit ex352 to perform spread spectrumprocessing on the text data, and the transmitting and receiving unitex351 performs the digital-to-analog conversion and the frequencyconversion on the resulting data to transmit the data to the basestation ex110 via the antenna ex350. When an e-mail is received,processing that is approximately inverse to the processing fortransmitting an e-mail is performed on the received data, and theresulting data is provided to the display unit ex358.

When video, still images, or video and audio in data communication modeis or are transmitted, the video signal processing unit ex355 (that is,functioning as the image coding apparatus according to the aspect of thepresent disclosure) compresses and codes video signals supplied from thecamera unit ex365 using the moving picture coding method shown in eachof Embodiments, and transmits the coded video data to themultiplexing/demultiplexing unit ex353. In contrast, during when thecamera unit ex365 captures video, still images, and others, the audiosignal processing unit ex354 codes audio signals collected by the audioinput unit ex356, and transmits the coded audio data to themultiplexing/demultiplexing unit ex353.

The multiplexing/demultiplexing unit ex353 multiplexes the coded videodata supplied from the video signal processing unit ex355 and the codedaudio data supplied from the audio signal processing unit ex354, using apredetermined method. Then, the modulation/demodulation unit ex352performs spread spectrum processing on the multiplexed data, and thetransmitting and receiving unit ex351 performs digital-to-analogconversion and frequency conversion on the data so as to transmit theresulting data via the antenna ex350.

When receiving data of a video file which is linked to a Web page andothers in data communication mode or when receiving an e-mail with videoand/or audio attached, in order to decode the multiplexed data receivedvia the antenna ex350, the multiplexing/demultiplexing unit ex353demultiplexes the multiplexed data into a video data bit stream and anaudio data bit stream, and supplies the video signal processing unitex355 with the coded video data and the audio signal processing unitex354 with the coded audio data, through the synchronous bus ex370. Thevideo signal processing unit ex355 (that is, functioning as the imagedecoding apparatus according to the aspect of the present disclosure)decodes the video signal using a moving picture decoding methodcorresponding to the moving picture coding method shown in each ofEmbodiments, and then the display unit ex358 displays, for instance, thevideo and still images included in the video file linked to the Web pagevia the LCD control unit ex359. Furthermore, the audio signal processingunit ex354 decodes the audio signal, and the audio output unit ex357provides the audio.

Furthermore, similarly to the television ex300, a terminal such as thecellular phone ex114 probably have 3 types of implementationconfigurations including not only (i) a transmitting and receivingterminal including both a coding apparatus and a decoding apparatus, butalso (ii) a transmitting terminal including only a coding apparatus and(iii) a receiving terminal including only a decoding apparatus. Althoughthe digital broadcasting system ex200 receives and transmits themultiplexed data obtained by multiplexing audio data onto video data inthe description, the multiplexed data may be data obtained bymultiplexing not audio data but character data related to video ontovideo data, and may be not multiplexed data but video data itself.

As such, the moving picture coding method or the moving picture decodingmethod in each of Embodiments can be used in any of the devices andsystems described. Thus, the advantages described in each of Embodimentscan be obtained.

Furthermore, the present disclosure is not limited to Embodiments, andvarious modifications and revisions are possible without departing fromthe scope of the present disclosure.

Embodiment 4

Video data can be generated by switching, as necessary, between (i) themoving picture coding method or the moving picture coding apparatusshown in each of Embodiments and (ii) a moving picture coding method ora moving picture coding apparatus in conformity with a differentstandard, such as MPEG-2, MPEG4-AVC, and VC-1.

Here, when a plurality of video data that conforms to the differentstandards is generated and is then decoded, the decoding methods need tobe selected to conform to the different standards. However, since towhich standard each of the plurality of the video data to be decodedconforms cannot be detected, there is a problem that an appropriatedecoding method cannot be selected.

In order to solve the problem, multiplexed data obtained by multiplexingaudio data and others onto video data has a structure includingidentification information indicating to which standard the video dataconforms. The specific structure of the multiplexed data including thevideo data generated in the moving picture coding method or by themoving picture coding apparatus shown in each of Embodiments will behereinafter described. The multiplexed data is a digital stream in theMPEG-2 Transport Stream format.

FIG. 26 illustrates a structure of multiplexed data. As illustrated inFIG. 26, the multiplexed data can be obtained by multiplexing at leastone of a video stream, an audio stream, a presentation graphics stream(PG), and an interactive graphics stream. The video stream representsprimary video and secondary video of a movie, the audio stream (IG)represents a primary audio part and a secondary audio part to be mixedwith the primary audio part, and the presentation graphics streamrepresents subtitles of a movie. Here, the primary video is normal videoto be displayed on a screen, and the secondary video is video to bedisplayed on a smaller window in the main video. Furthermore, theinteractive graphics stream represents an interactive screen to begenerated by arranging the GUI components on a screen. The video streamis coded in the moving picture coding method or by the moving picturecoding apparatus shown in each of Embodiments, or in a moving picturecoding method or by a moving picture coding apparatus in conformity witha conventional standard, such as MPEG-2, MPEG4-AVC, and VC-1. The audiostream is coded in accordance with a standard, such as Dolby-AC-3, DolbyDigital Plus, MLP, DTS, DTS-HD, and linear PCM.

Each stream included in the multiplexed data is identified by PID. Forexample, 0x1011 is allocated to the video stream to be used for video ofa movie, 0x1100 to 0x111F are allocated to the audio streams, 0x1200 to0x121F are allocated to the presentation graphics streams, 0x1400 to0x141F are allocated to the interactive graphics streams, 0x1B00 to0x1B1F are allocated to the video streams to be used for secondary videoof the movie, and 0x1A00 to 0x1A1F are allocated to the audio streams tobe used for the secondary video to be mixed with the primary audio.

FIG. 27 schematically illustrates how data is multiplexed. First, avideo stream ex235 composed of video frames and an audio stream ex238composed of audio frames are transformed into a stream of PES packetsex236 and a stream of PES packets ex239, and further into TS packetsex237 and TS packets ex240, respectively. Similarly, data of apresentation graphics stream ex241 and data of an interactive graphicsstream ex244 are transformed into a stream of PES packets ex242 and astream of PES packets ex245, and further into TS packets ex243 and TSpackets ex246, respectively. These TS packets are multiplexed into astream to obtain multiplexed data ex247.

FIG. 28 illustrates how a video stream is stored in a stream of PESpackets in more detail. The first bar in FIG. 28 shows a video framestream in a video stream. The second bar shows the stream of PESpackets. As indicated by arrows yy1, yy2, yy3, and yy4 in FIG. 28, thevideo stream is divided into pictures as I pictures, B pictures, and Ppictures each of which is a video presentation unit, and the picturesare stored in a payload of each of the PES packets. Each of the PESpackets has a PES header, and the PES header stores a PresentationTime-Stamp (PTS) indicating a display time of the picture, and aDecoding Time-Stamp (DTS) indicating a decoding time of the picture.

FIG. 29 illustrates a format of TS packets to be finally written on themultiplexed data. Each of the TS packets is a 188-byte fixed lengthpacket including a 4-byte TS header having information, such as a PIDfor identifying a stream and a 184-byte TS payload for storing data. ThePES packets are divided, and stored in the TS payloads. When a BD ROM isused, each of the TS packets is given a 4-byte TP_Extra_Header, thusresulting in 192-byte source packets. The source packets are written onthe multiplexed data. The TP_Extra_Header stores information such as anArrival_Time_Stamp (ATS). The ATS shows a transfer start time at whicheach of the TS packets is to be transferred to a PID filter. The numbersincrementing from the head of the multiplexed data are called sourcepacket numbers (SPNs) as shown at the bottom of FIG. 29.

Each of the TS packets included in the multiplexed data includes notonly streams of audio, video, subtitles and others, but also a ProgramAssociation Table (PAT), a Program Map Table (PMT), and a Program ClockReference (PCR). The PAT shows what a PID in a PMT used in themultiplexed data indicates, and a PID of the PAT itself is registered aszero. The PMT stores PIDs of the streams of video, audio, subtitles andothers included in the multiplexed data, and attribute information ofthe streams corresponding to the PIDs. The PMT also has variousdescriptors relating to the multiplexed data. The descriptors haveinformation such as copy control information showing whether copying ofthe multiplexed data is permitted or not. The PCR stores STC timeinformation corresponding to an ATS showing when the PCR packet istransferred to a decoder, in order to achieve synchronization between anArrival Time Clock (ATC) that is a time axis of ATSs, and an System TimeClock (STC) that is a time axis of PTSs and DTSs.

FIG. 30 illustrates the data structure of the PMT in detail. A PMTheader is disposed at the top of the PMT. The PMT header describes thelength of data included in the PMT and others. A plurality ofdescriptors relating to the multiplexed data is disposed after the PMTheader. Information such as the copy control information is described inthe descriptors. After the descriptors, a plurality of pieces of streaminformation relating to the streams included in the multiplexed data isdisposed. Each piece of stream information includes stream descriptorseach describing information, such as a stream type for identifying acompression codec of a stream, a stream PID, and stream attributeinformation (such as a frame rate or an aspect ratio). The streamdescriptors are equal in number to the number of streams in themultiplexed data.

When the multiplexed data is recorded on a recording medium and others,it is recorded together with multiplexed data information files.

Each of the multiplexed data information files is management informationof the multiplexed data as shown in FIG. 31. The multiplexed datainformation files are in one to one correspondence with the multiplexeddata, and each of the files includes multiplexed data information,stream attribute information, and an entry map.

As illustrated in FIG. 31, the multiplexed data information includes asystem rate, a reproduction start time, and a reproduction end time. Thesystem rate indicates the maximum transfer rate at which a system targetdecoder to be described later transfers the multiplexed data to a PIDfilter. The intervals of the ATSs included in the multiplexed data areset to not higher than a system rate. The reproduction start timeindicates a PTS in a video frame at the head of the multiplexed data. Aninterval of one frame is added to a PTS in a video frame at the end ofthe multiplexed data, and the PTS is set to the reproduction end time.

As shown in FIG. 32, a piece of attribute information is registered inthe stream attribute information, for each PID of each stream includedin the multiplexed data. Each piece of attribute information hasdifferent information depending on whether the corresponding stream is avideo stream, an audio stream, a presentation graphics stream, or aninteractive graphics stream. Each piece of video stream attributeinformation carries information including what kind of compression codecis used for compressing the video stream, and the resolution, aspectratio and frame rate of the pieces of picture data that is included inthe video stream. Each piece of audio stream attribute informationcarries information including what kind of compression codec is used forcompressing the audio stream, how many channels are included in theaudio stream, which language the audio stream supports, and how high thesampling frequency is. The video stream attribute information and theaudio stream attribute information are used for initialization of adecoder before the player plays back the information.

In Embodiment 4, the multiplexed data to be used is of a stream typeincluded in the PMT. Furthermore, when the multiplexed data is recordedon a recording medium, the video stream attribute information includedin the multiplexed data information is used. More specifically, themoving picture coding method or the moving picture coding apparatusdescribed in each of Embodiments includes a step or a unit forallocating unique information indicating video data generated by themoving picture coding method or the moving picture coding apparatus ineach of Embodiments, to the stream type included in the PMT or the videostream attribute information. With the structure, the video datagenerated by the moving picture coding method or the moving picturecoding apparatus described in each of Embodiments can be distinguishedfrom video data that conforms to another standard.

Furthermore, FIG. 33 illustrates steps of the moving picture decodingmethod according to Embodiment 4. In Step exS100, the stream typeincluded in the PMT or the video stream attribute information isobtained from the multiplexed data. Next, in Step exS101, it isdetermined whether or not the stream type or the video stream attributeinformation indicates that the multiplexed data is generated by themoving picture coding method or the moving picture coding apparatus ineach of Embodiments. When it is determined that the stream type or thevideo stream attribute information indicates that the multiplexed datais generated by the moving picture coding method or the moving picturecoding apparatus in each of Embodiments, in Step exS102, the stream typeor the video stream attribute information is decoded by the movingpicture decoding method in each of Embodiments. Furthermore, when thestream type or the video stream attribute information indicatesconformance to the conventional standards, such as MPEG-2, MPEG4-AVC,and VC-1, in Step exS103, the stream type or the video stream attributeinformation is decoded by a moving picture decoding method in conformitywith the conventional standards.

As such, allocating a new unique value to the stream type or the videostream attribute information enables determination whether or not themoving picture decoding method or the moving picture decoding apparatusthat is described in each of Embodiments can perform decoding. Even uponan input of multiplexed data that conforms to a different standard, anappropriate decoding method or apparatus can be selected. Thus, itbecomes possible to decode information without any error. Furthermore,the moving picture coding method or apparatus, or the moving picturedecoding method or apparatus in Embodiment 4 can be used in the devicesand systems described above.

Embodiment 5

Each of the moving picture coding method, the moving picture codingapparatus, the moving picture decoding method, and the moving picturedecoding apparatus in each of Embodiments is typically achieved in theform of an integrated circuit or a Large Scale Integrated (LSI) circuit.As an example of the LSI, FIG. 34 illustrates a configuration of the LSIex500 that is made into one chip. The LSI ex500 includes elements ex501,ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509 to bedescribed below, and the elements are connected to each other through abus ex510. The power supply circuit unit ex505 is activated by supplyingeach of the elements with power when the power supply circuit unit ex505is turned on.

For example, when coding is performed, the LSI ex500 receives an AVsignal from a microphone ex117, a camera ex113, and others through an AVIO ex509 under control of a control unit ex501 including a CPU ex502, amemory controller ex503, a stream controller ex504, and a drivingfrequency control unit ex512. The received AV signal is temporarilystored in an external memory ex511, such as an SDRAM. Under control ofthe control unit ex501, the stored data is segmented into data portionsaccording to the processing amount and speed to be transmitted to asignal processing unit ex507. Then, the signal processing unit ex507codes an audio signal and/or a video signal. Here, the coding of thevideo signal is the coding described in each of Embodiments.Furthermore, the signal processing unit ex507 sometimes multiplexes thecoded audio data and the coded video data, and a stream IO ex506provides the multiplexed data outside. The provided multiplexed data istransmitted to the base station ex107, or written on the recording mediaex215. When data sets are multiplexed, the data sets should betemporarily stored in the buffer ex508 so that the data sets aresynchronized with each other.

Although the memory ex511 is an element outside the LSI ex500, it may beincluded in the LSI ex500. The buffer ex508 is not limited to onebuffer, but may be composed of buffers. Furthermore, the LSI ex500 maybe made into one chip or a plurality of chips.

Furthermore, although the control unit ex501 includes the CPU ex502, thememory controller ex503, the stream controller ex504, the drivingfrequency control unit ex512, the configuration of the control unitex501 is not limited to such. For example, the signal processing unitex507 may further include a CPU. Inclusion of another CPU in the signalprocessing unit ex507 can improve the processing speed. Furthermore, asanother example, the CPU ex502 may include the signal processing unitex507, or an audio signal processing unit that is a part of the signalprocessing unit ex507. In such a case, the control unit ex501 includesthe signal processing unit ex507 or the CPU ex502 including a part ofthe signal processing unit ex507.

The name used here is LSI, but it may also be called IC, system LSI,super LSI, or ultra LSI depending on the degree of integration.

Moreover, ways to achieve integration are not limited to the LSI, and aspecial circuit or a general purpose processor and so forth can alsoachieve the integration. Field Programmable Gate Array (FPGA) that canbe programmed after manufacturing LSIs or a reconfigurable processorthat allows re-configuration of the connection or configuration of anLSI can be used for the same purpose. The programmable logic device cantypically execute the moving picture coding method and the movingpicture decoding method according to Embodiments and Variations, byloading or reading, from a memory, the program included in software orfirmware.

In the future, with advancement in semiconductor technology, a brand-newtechnology may replace LSI. The functional blocks can be integratedusing such a technology. The possibility is that the present disclosureis applied to biotechnology.

Embodiment 6

When video data generated by the moving picture coding method or by themoving picture coding apparatus described in each of Embodiments isdecoded, compared to the case of decoding video data that conforms to aconventional standard, such as MPEG-2, MPEG4-AVC, and VC-1, thecomputing amount probably increases. Thus, the LSI ex500 needs to be setto a driving frequency higher than that of the CPU ex502 to be used whenvideo data in conformity with the conventional standard is decoded.However, when the driving frequency is set higher, there is a problemthat the power consumption increases.

In order to solve the problem, the moving picture decoding apparatus,such as the television ex300 and the LSI ex500 is configured todetermine to which standard the video data conforms, and switch betweenthe driving frequencies according to the determined standard. FIG. 35illustrates a configuration ex800 in Embodiment 6. A driving frequencyswitching unit ex803 sets a driving frequency to a higher drivingfrequency when video data is generated by the moving picture codingmethod or the moving picture coding apparatus described in each ofEmbodiments. Then, the driving frequency switching unit ex803 instructsa decoding processing unit ex801 that executes the moving picturedecoding method described in each of Embodiments to decode the videodata. When the video data conforms to the conventional standard, thedriving frequency switching unit ex803 sets a driving frequency to alower driving frequency than that of the video data generated by themoving picture coding method or the moving picture coding apparatusdescribed in each of Embodiments. Then, the driving frequency switchingunit ex803 instructs the decoding processing unit ex802 that conforms tothe conventional standard to decode the video data.

More specifically, the driving frequency switching unit ex803 includesthe CPU ex502 and the driving frequency control unit ex512 in FIG. 34.Here, each of the decoding processing unit ex801 that executes themoving picture decoding method described in each of Embodiments and thedecoding processing unit ex802 that conforms to the conventionalstandard corresponds to the signal processing unit ex507 in FIG. 34. TheCPU ex502 determines to which standard the video data conforms. Then,the driving frequency control unit ex512 determines a driving frequencybased on a signal from the CPU ex502. Furthermore, the signal processingunit ex507 decodes the video data based on a signal from the CPU ex502.For example, the identification information described in Embodiment 4 isprobably used for identifying the video data. The identificationinformation is not limited to the one described in Embodiment 4 but maybe any information as long as the information indicates to whichstandard the video data conforms. For example, when which standard videodata conforms to can be determined based on an external signal fordetermining that the video data is used for a television or a disk,etc., the determination may be made based on such an external signal.Furthermore, the CPU ex502 selects a driving frequency based on, forexample, a look-up table in which the standards of the video data areassociated with the driving frequencies as shown in FIG. 37. The drivingfrequency can be selected by storing the look-up table in the bufferex508 and an internal memory of an LSI, and with reference to thelook-up table by the CPU ex502.

FIG. 36 illustrates steps for executing a method in Embodiment 6. First,in Step exS200, the signal processing unit ex507 obtains identificationinformation from the multiplexed data. Next, in Step exS201, the CPUex502 determines whether or not the video data is generated based on theidentification information by the coding method and the coding apparatusdescribed in each of Embodiments. When the video data is generated bythe coding method or the coding apparatus described in each ofEmbodiments, in Step exS202, the CPU ex502 transmits a signal forsetting the driving frequency to a higher driving frequency to thedriving frequency control unit ex512. Then, the driving frequencycontrol unit ex512 sets the driving frequency to the higher drivingfrequency. On the other hand, when the identification informationindicates that the video data conforms to the conventional standard,such as MPEG-2, MPEG4-AVC, and VC-1, in Step exS203, the CPU ex502transmits a signal for setting the driving frequency to a lower drivingfrequency to the driving frequency control unit ex512. Then, the drivingfrequency control unit ex512 sets the driving frequency to the lowerdriving frequency than that in the case where the video data isgenerated by the coding method or the coding apparatus described in eachof Embodiments.

Furthermore, along with the switching of the driving frequencies, thepower conservation effect can be improved by changing the voltage to beapplied to the LSI ex500 or an apparatus including the LSI ex500. Forexample, when the driving frequency is set lower, the voltage to beapplied to the LSI ex500 or the apparatus including the LSI ex500 isprobably set to a voltage lower than that in the case where the drivingfrequency is set higher.

Furthermore, when the computing amount for decoding is larger, thedriving frequency may be set higher, and when the computing amount fordecoding is smaller, the driving frequency may be set lower as themethod for setting the driving frequency. Thus, the setting method isnot limited to the ones described above. For example, when the computingamount for decoding video data in conformity with MPEG4-AVC is largerthan the computing amount for decoding video data generated by themoving picture coding method or the moving picture coding apparatusdescribed in each of Embodiments, the driving frequency is probably setin reverse order to the setting described above.

Furthermore, the method for setting the driving frequency is not limitedto the method for setting the driving frequency lower. For example, whenthe identification information indicates that the video data isgenerated by the moving picture coding method or the moving picturecoding apparatus described in each of Embodiments, the voltage to beapplied to the LSI ex500 or the apparatus including the LSI ex500 isprobably set higher. When the identification information indicates thatthe video data conforms to the conventional standard, such as MPEG-2,MPEG4-AVC, and VC-1, the voltage to be applied to the LSI ex500 or theapparatus including the LSI ex500 is probably set lower. As anotherexample, when the identification information indicates that the videodata is generated by the moving picture coding method or the videocoding apparatus described in each of Embodiments, the driving of theCPU ex502 does not probably have to be suspended. When theidentification information indicates that the video data conforms to theconventional standard, such as MPEG-2, MPEG4-AVC, and VC-1, the drivingof the CPU ex502 is probably suspended at a given time because the CPUex502 has extra processing capacity. Even when the identificationinformation indicates that the video data is generated by the movingpicture coding method or the moving picture coding apparatus describedin each of Embodiments, in the case where the CPU ex502 has extraprocessing capacity, the driving of the CPU ex502 is probably suspendedat a given time. In such a case, the suspending time is probably setshorter than that in the case where when the identification informationindicates that the video data conforms to the conventional standard,such as MPEG-2, MPEG4-AVC, and VC-1.

Accordingly, the power conservation effect can be improved by switchingbetween the driving frequencies in accordance with the standard to whichthe video data conforms. Furthermore, when the LSI ex500 or theapparatus including the LSI ex500 is driven using a battery, the batterylife can be extended with the power conservation effect.

Embodiment 7

There are cases where a plurality of video data that conforms todifferent standards, is provided to the devices and systems, such as atelevision and a cellular phone. In order to enable decoding theplurality of video data that conforms to the different standards, thesignal processing unit ex507 of the LSI ex500 needs to conform to thedifferent standards. However, the problems of increase in the scale ofthe circuit of the LSI ex500 and increase in the cost arise with theindividual use of the signal processing units ex507 that conform to therespective standards.

In order to solve the problems, what is conceived is a configuration inwhich the decoding processing unit for implementing the moving picturedecoding method described in each of Embodiments and the decodingprocessing unit that conforms to the conventional standard, such asMPEG-2, MPEG4-AVC, and VC-1 are partly shared. Ex900 in FIG. 38A showsan example of the configuration. For example, the moving picturedecoding method described in each of Embodiments and the moving picturedecoding method that conforms to MPEG4-AVC have, partly in common, thedetails of processing, such as entropy coding, inverse quantization,deblocking filtering, and motion compensation. The details of processingto be shared probably include use of a decoding processing unit ex902that conforms to MPEG4-AVC. In contrast, a dedicated decoding processingunit ex901 is probably used for other processing which is unique to thepresent disclosure and does not conform to MPEG-4 AVC. Since the aspectof the present disclosure particularly features entropy decoding, forexample, the dedicated decoding processing unit ex901 is used for theentropy decoding. Otherwise, the decoding processing unit is probablyshared for one of inverse quantization, deblocking filtering, and motioncompensation, or all of the processing. The decoding processing unit forimplementing the moving picture decoding method described in each ofEmbodiments may be shared for the processing to be shared, and adedicated decoding processing unit may be used for processing unique tothat of MPEG4-AVC.

Furthermore, ex1000 in FIG. 38B shows another example in whichprocessing is partly shared. This example uses a configuration includinga dedicated decoding processing unit ex1001 that supports the processingunique to the aspect of the present disclosure, a dedicated decodingprocessing unit ex1002 that supports the processing unique to anotherconventional standard, and a decoding processing unit ex1003 thatsupports processing to be shared between the moving picture decodingmethod in the aspect of the present disclosure and the conventionalmoving picture decoding method. Here, the dedicated decoding processingunits ex1001 and ex1002 are not necessarily specialized for theprocessing of the aspect of the present disclosure and the processing ofthe conventional standard, and may be the ones capable of implementinggeneral processing. Furthermore, the configuration of Embodiment 7 canbe implemented by the LSI ex500.

As such, reducing the scale of the circuit of an LSI and reducing thecost are possible by sharing the decoding processing unit for theprocessing to be shared between the moving picture decoding method inthe present disclosure and the moving picture decoding method inconformity with the conventional standard.

The herein disclosed subject matter is to be considered descriptive andillustrative only, and the appended Claims are of a scope intended tocover and encompass not only the particular embodiments disclosed, butalso equivalent structures, methods, and/or uses.

INDUSTRIAL APPLICABILITY

The moving picture coding apparatus or the moving picture decodingapparatus according to an aspect of the present disclosure is applicableto, for example, television receivers, digital video recorders, carnavigation systems, mobile phones, digital cameras, and digital videocameras.

1-15. (canceled)
 16. A moving picture coding method for coding an inputimage, the method comprising: converting, using a binarizer, a value ofa first parameter into a first binary signal, the first parameteridentifying a type of a sample offset process to be applied to areconstructed image corresponding to the input image; coding a firstportion of the first binary signal through context-adaptive arithmeticcoding; and coding, when a value of the first portion of the firstbinary signal is greater than or equal to a predetermined value, asecond portion of the first binary signal through bypass arithmeticcoding using a fixed probability, wherein a variable probability is notused in the bypass arithmetic coding, the first portion of the firstbinary signal is composed of a head bit of the first binary signal, andthe second portion of the first binary signal is composed of one or moreremaining bits of the first binary signal.
 17. A moving picture codingapparatus that codes an input image, the apparatus comprising: aconverter that converts, using a binarizer, a value of a first parameterinto a first binary signal, the first parameter identifying a type of asample offset process to be applied to a reconstructed imagecorresponding to the input image; a first coder that codes a firstportion of the first binary signal through context-adaptive arithmeticcoding; and a second coder that codes, when a value of the first portionof the first binary signal is greater than or equal to a predeterminedvalue, a second portion of the first binary signal through bypassarithmetic coding using a fixed probability, wherein a variableprobability is not used in the bypass arithmetic coding, the firstportion of the first binary signal is composed of a head bit of thefirst binary signal, and the second portion of the first binary signalis composed of one or more remaining bits of the first binary signal.